I Am Legend

In I Am Legend, Will Smith, as a U.S. Army officer who may be the last man on earth, drives at top speeds through the concrete valleys of Manhattan, which have been deserted for so long that the cracks in the roads now sprout scruffy green weeds. For sheer eeriness, that effect — the metropolis as vacant lot — far outdoes the desolate Times Square of Vanilla Sky, and Smith is the perfect actor (maybe almost too perfect) to play a survivor who has no one to talk to but his dog and himself. Smith has always worn his self-sufficiency like a suit of armor, often treating costars as sounding boards; he brings that jaunty insularity to the abandoned canyons of a trashed Twilight Zone New York. Here, though, he also draws on the vulnerability he showed last year in The Pursuit of Happyness, suggesting a man whose sanity is beginning to fray.

Based on Richard Matheson's 1954 novel, I Am Legend is a spooky-hokey postapocalyptic thriller built around our fear of contagion (the premise is that a ''miracle'' cancer cure has wiped out the earth's population). It's a movie that might have fit snugly into the zeitgeist had it been made in the early '90s, or maybe 1971 — when, in fact, it was made as The Omega Man, a somber but colossally silly Charlton Heston thriller. Let's be honest: The peril of infectious disease, while quite real, is hardly the anxiety of the moment. In spirit, I Am Legend is caught in some abstractly doom-laden sci-fi past. For what it is, though, the film is well-done, a case of suspenseful competence trumping questionable relevance.

There's one scary sequence in which Smith follows his dog into a warehouse, but as soon as you see the prancing, gnashing, veiny mutant humanoids who have taken up refuge there, you think, ''Okay, it's a fake-demon CGI movie.'' And so it is, though at least it never becomes a soulless monster-hunt videogame like Resident Evil. Smith, who keeps the movie grounded, isn't just surviving — he's on a mission. In The Omega Man, Heston faced a cult of white-faced hippie mutants in sunglasses and medieval monks' robes. Sometimes, CGI really is an advance.